This document discusses oxidation and reduction reactions and provides rules for determining oxidation numbers: 1) Oxidation involves loss of electrons and increases oxidation number, while reduction involves gain of electrons and decreases oxidation number. 2) The sum of oxidation numbers in a molecule or ion must equal the overall charge. 3) Transition metals can have variable oxidation numbers depending on their compounds. Their oxidation states are included in names. 4) Some anomalies may occur where oxidation numbers are fractional or elements appear to gain/lose no electrons.